engine.#Build support

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

plan/task/build.go

@@ -0,0 +1,219 @@
+package task
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"cuelang.org/go/cue"
+	bkplatforms "github.com/containerd/containerd/platforms"
+	"github.com/moby/buildkit/client/llb"
+	"github.com/moby/buildkit/exporter/containerimage/exptypes"
+	dockerfilebuilder "github.com/moby/buildkit/frontend/dockerfile/builder"
+	"github.com/moby/buildkit/frontend/dockerfile/dockerfile2llb"
+	bkgw "github.com/moby/buildkit/frontend/gateway/client"
+	bkpb "github.com/moby/buildkit/solver/pb"
+
+	"go.dagger.io/dagger/compiler"
+	"go.dagger.io/dagger/plancontext"
+	"go.dagger.io/dagger/solver"
+)
+
+func init() {
+	Register("Build", func() Task { return &buildTask{} })
+}
+
+type buildTask struct {
+}
+
+func (t *buildTask) Run(ctx context.Context, pctx *plancontext.Context, s solver.Solver, v *compiler.Value) (*compiler.Value, error) {
+	frontend, err := v.Lookup("frontend").String()
+	if err != nil {
+		return nil, err
+	}
+
+	switch frontend {
+	case "dockerfile":
+		return t.dockerfile(ctx, pctx, s, v)
+	default:
+		return nil, fmt.Errorf("unsupported frontend %q", frontend)
+	}
+}
+
+func (t *buildTask) dockerfile(ctx context.Context, pctx *plancontext.Context, s solver.Solver, v *compiler.Value) (*compiler.Value, error) {
+	// FIXME: support auth
+
+	source, err := pctx.FS.FromValue(v.Lookup("source"))
+	if err != nil {
+		return nil, err
+	}
+
+	sourceSt, err := source.Result().ToState()
+	if err != nil {
+		return nil, err
+	}
+
+	// docker build context
+	contextDef, err := s.Marshal(ctx, sourceSt)
+	if err != nil {
+		return nil, err
+	}
+	// Dockerfile context, default to docker build context
+	dockerfileDef := contextDef
+
+	// Support inlined dockerfile
+	if dockerfile := v.Lookup("dockerfile.contents"); dockerfile.Exists() {
+		contents, err := dockerfile.String()
+		if err != nil {
+			return nil, err
+		}
+		dockerfileDef, err = s.Marshal(ctx,
+			llb.Scratch().File(
+				llb.Mkfile("/Dockerfile", 0644, []byte(contents)),
+			),
+		)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	opts, err := t.dockerBuildOpts(v, pctx)
+	if err != nil {
+		return nil, err
+	}
+	// Handle --no-cache
+	if s.NoCache() {
+		opts["no-cache"] = ""
+	}
+
+	req := bkgw.SolveRequest{
+		Frontend:    "dockerfile.v0",
+		FrontendOpt: opts,
+		FrontendInputs: map[string]*bkpb.Definition{
+			dockerfilebuilder.DefaultLocalNameContext:    contextDef,
+			dockerfilebuilder.DefaultLocalNameDockerfile: dockerfileDef,
+		},
+	}
+	res, err := s.SolveRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	ref, err := res.SingleRef()
+	if err != nil {
+		return nil, err
+	}
+
+	out := compiler.NewValue()
+	if err := out.FillPath(cue.ParsePath("output"), pctx.FS.New(ref).MarshalCUE()); err != nil {
+		return nil, err
+	}
+
+	// Load image metadata
+	if meta, ok := res.Metadata[exptypes.ExporterImageConfigKey]; ok {
+		var image dockerfile2llb.Image
+		if err := json.Unmarshal(meta, &image); err != nil {
+			return nil, fmt.Errorf("failed to unmarshal image config: %w", err)
+		}
+		if err := out.FillPath(cue.ParsePath("config"), image.Config); err != nil {
+			return nil, err
+		}
+	}
+
+	return out, nil
+}
+
+func (t *buildTask) dockerBuildOpts(v *compiler.Value, pctx *plancontext.Context) (map[string]string, error) {
+	opts := map[string]string{}
+
+	if dockerfilePath := v.Lookup("dockerfile.path"); dockerfilePath.Exists() {
+		filename, err := dockerfilePath.String()
+		if err != nil {
+			return nil, err
+		}
+		opts["filename"] = filename
+	}
+
+	if target := v.Lookup("target"); target.Exists() {
+		tgr, err := target.String()
+		if err != nil {
+			return nil, err
+		}
+		opts["target"] = tgr
+	}
+
+	if hosts := v.Lookup("hosts"); hosts.Exists() {
+		p := []string{}
+		fields, err := hosts.Fields()
+		if err != nil {
+			return nil, err
+		}
+		for _, host := range fields {
+			s, err := host.Value.String()
+			if err != nil {
+				return nil, err
+			}
+			p = append(p, host.Label()+"="+s)
+		}
+		if len(p) > 0 {
+			opts["add-hosts"] = strings.Join(p, ",")
+		}
+	}
+
+	if buildArgs := v.Lookup("buildArg"); buildArgs.Exists() {
+		fields, err := buildArgs.Fields()
+		if err != nil {
+			return nil, err
+		}
+		for _, buildArg := range fields {
+			s, err := buildArg.Value.String()
+			if err != nil {
+				return nil, err
+			}
+			opts["build-arg:"+buildArg.Label()] = s
+		}
+	}
+
+	if labels := v.Lookup("label"); labels.Exists() {
+		fields, err := labels.Fields()
+		if err != nil {
+			return nil, err
+		}
+		for _, label := range fields {
+			s, err := label.Value.String()
+			if err != nil {
+				return nil, err
+			}
+			opts["label:"+label.Label()] = s
+		}
+	}
+
+	if platforms := v.Lookup("platforms"); platforms.Exists() {
+		p := []string{}
+		list, err := platforms.List()
+		if err != nil {
+			return nil, err
+		}
+
+		for _, platform := range list {
+			s, err := platform.String()
+			if err != nil {
+				return nil, err
+			}
+			p = append(p, s)
+		}
+
+		if len(p) > 0 {
+			opts["platform"] = strings.Join(p, ",")
+		}
+		if len(p) > 1 {
+			opts["multi-platform"] = "true"
+		}
+	}
+	// Set platform to configured one if no one is defined
+	if opts["platform"] == "" {
+		opts["platform"] = bkplatforms.Format(pctx.Platform.Get())
+	}
+
+	return opts, nil
+}